Immune function studies

Nutrition assessment is the first step in developing a nutrition care plan and includes a clinical evaluation, anthropometric measurements, and biochemical and immune function studies. 

The expanding field of avian immunoecology has provided strong evidence that suppressed immunity leads to ecologically relevant consequences in wild birds. In a review of 12 immune function studies, immune responses were the most significant predictors of subsequent survival of young wild birds [107], In an assessment of 280 introduction attempts in 38 avian species, immunocompetence as assessed by the PHA skin response was an important positive predictor of the ability of birds to colonize new areas (i.e., found new local populations) [108], Similar assessments of survival, fitness, and dispersal ability should be conducted within the context of immunotoxicological studies of wild birds. 

Weeks et al. 1979). Responses of this sort may be due, in part, to compromised immune functions. Studies in animals, using a battery of in vitro and short-term in vivo studies of immunotoxicity following inhalation and oral exposure, may enhance our overall understanding of the effects of hexachloroethane on disease resistance. 

Seinen, W., Vos, J.G. and Van Loveren, H. (1993) Immunotoxic effects of the color additive caramel color 111 immune function studies in rats. Fundamental and Applied Toxicology, 20, 30-37. 

If the weight-of-evidence review indicates that additional immunotoxicity studies are needed, there are a number of assays which can be used. It is recommended that an immune function study be conducted, such as a T-cell dependent antibody response (TDAR). If specific cell types are affected in STS not involving cells participating in a TDAR, assays that measure... 

Holt, P.G. and Schon-Hegrad, M.A. (1987). Localization of T cells, macrophages and dendritic cells in rat respiratory tract tissue implications for immune function studies. 

Immune function studies were subsequently performed on mice rendered tolerant or abstinent by this procedure. Neither tolerance nor abstinence to the 4-day THC administration had any effect on bodyweight or thymus weight and cellularity, although spleen weight and cellularity were both decreased in THC-abstinent animals. 

Vitamin E (alpha-tocopherol) has been the subject of several cancer prevention and immune function studies because of its ability to neutralize free radicals, but results have been mixed. If you use diet to boost vitamin E, it is important to balance how much you consume of some of its richest sources since many are high-fat foods. Avocado, olive oil, canola oil, almonds, and hazelnuts are examples. 

Chemical-mediated immune suppression has been identified from the experimental study of several wildlife species. Harbour seals fed either chemically contaminated fish from the Wadden Sea or imcontaminated fish were found to have differing immune responses, with the exposed group showing lowered immune response to microbial infections and certain types of cancer. "" Mink fed fish taken from below a discharge point for bleached Kraft pulp mill effluent have also shown impaired immune function, " showing that the non-accnmillative chemicals in this effluent can actively disrupt endocrine associated functions. 

To study the effect of an increased gene dosage of GR, Reichardt et al. (2000) and van den Brandt et al. (2007) generated rodent models of GR overexpression. These approaches confirmed that GR controls neuronal and immune functions in a dosage-dependent manner. These results highlight the importance of tight control of GR expression in target tissues and may explain... 

Also, chronic-duration studies have not generally shown adverse effects on organs of the immune system. Routine gross and histopathologic examination of the lymph nodes and thymus of rats, mice, and dogs exposed to endosulfan for 2 years at doses of up to 2.9 mg/kg/day (Hoechst 1989a), 2.51 mg/kg/day (Hoechst 1988b), and 1 mg/kg/day (EMC 1967), respectively, revealed no adverse effects. However, these studies did not assess immune function directly. 

Since initial studies identified opioid receptors on T-lymphocytes (Wybran et al. 1979), the effects of opioids on immune function have been extensively studied. Details of these studies have been exhaustively reviewed (Madden et al. 1991 Adler et al. 1993 Peterson et al. 1998 Donahoe and Vlahov 1998 Roy et al. 2006), and will only be briefly mentioned here. In general, opioids suppress immune function. Peripheral leukocytes, including lymphocytes and peripheral blood mononuclear cells (PBMCs) can express the four major opioid receptor types, MOP, DOP, KOP,... 

The sterols and sterolins in rice bran are potent immunomodulators. The best response was obtained with a 100 1 sterol/sterolin mixture that demonstrated T-cell proliferation from 20% to 920% and active cell antigens after four weeks in human subjects (Bouic et al, 1996). Another in vitro experimental study with sterol/sterolins, demonstrated a significant increase in cytokinines, interleukin-2 and y-interferon between 17% and 41 % in addition to an increase in natural killer cell activity. These experiments (Bouic et al, 1996) prove that sterol/sterolins are potent immunomodulators with important implications for the treatment of immune dysfunction. Rice bran products are excellent dietary supplements for the improvement of immune function. It is probable that the effects of rice bran on diabetes, CVD and cancer all result from improved immune function. 

Routine antioxidant vitamin supplementation, e.g. with vitamins C and/or E, of the diabetic diet should be considered. Vitamin C depletion is present in all diabetics irrespective of the presence of vascular disease. A recent study demonstrated no significant difference between the dietary intake of vitamin C (the main determinant of plasma ascorbate) in patients with diabetes and age-matched controls, confirming the view that ascorbate depletion is secondary to the diabetic process and su esting that diabetic patients require additional intakes of the vitamin to maintain optimal levels (Sinclair et /., 1994). Antioxidant supplementation may have additive beneficial effects on a wide variety of processes involved in diabetic vascular damage including blood pressure, immune function, inflammatory reactions. 

Additional studies of immune function in animals exposed to hydrogen sulfide by inhalation are needed. A bacterial and/or viral challenge study would be especially useful to determine whether exposure to hydrogen sulfide increases susceptibility to infection. 

The effects of acute- and intermediate-duration inhalation lead exposure on local and systemic immune function following intratracheal, intraperitoneal, or intravenous immunization were studied in mice continuously exposed to lead nitrate for 14 or 28 days (Hillam and Ozkan 1986). Several parameters of local and systemic immune function were measured in the immunized, lead-exposed mice. Lead content... 

Adverse kidney effects have been reported in rats exposed to lead during development (Fowler et al. 1980). Also, alterations in immune function have been observed in young rats exposed to lead perinatally (Faith et al. 1979 Luster et al. 1978). These studies are discussed in more detail in Sections 2.2.3.2 and 2.2.3.3. 

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